1. Field
The following description relates to an active joint module and a robot for inspecting pipelines having the active joint module, and more particularly, to an active joint module and a robot for inspecting pipelines that is capable of easily changing the driving direction of a robot for inspecting pipelines in a direction-variable area in a pipeline,
2. Description of Related Art
A pipeline is generally one of the structures of industrial infrastructure, which transfers various energy sources such as gas/petroleum, and distributes them to the right places on a timely basis.
Such pipelines are distributed here and there nationwide like blood vessels in a human body, and are being established as core infrastructure that continuously provide energy sources such as petroleum/gas to various city infrastructure and factory facilities. Furthermore, pipelines in large scale plants such as petrochemical plants are being used as major facilities to transfer various chemical materials that need to be refined and processed.
However, as a certain period of time passes after the pipelines are constructed, damages may occur in the pipelines due to corrosion caused by moisture and various chemical materials and effect by external environments, which may lead to leakage of the materials from inside the pipelines.
Leaking of petroleum and chemical materials may cause serious environmental pollution, and leaking of gas may cause big gas explosion accidents. Therefore, after a certain period of time has passed since the pipelines were installed, they need to be inspected and replaced on a regular basis.
Pipelines may be classified into extensive type pipelines and compact type pipelines depending on the type of installation. The extensive type pipelines are used for water and sewage lines, gas feeding lines, and petroleum feeding lines mainly in urban and national facilities. These types of pipelines are usually buried underground in order to prevent them from being damaged by external environment, to maintain the aesthetic urban landscape and to prevent them from being corroded, but since they are buried underground, they must be dug up every time they need to be repaired, or inspected, which is a disadvantage. The compact type pipelines are mainly used in plants such as petrochemical plants, and are entangled due to their complex transfer systems, and in many cases, they include route divergent areas (for example, divergent pipelines). The compact type pipelines have disadvantages that in order to inspect the pipelines in the inside, one has to take the trouble of removing the pipelines at the outside. Furthermore, pipelines installed in high places are not easily approachable.
Therefore, there has been a need for an inspection equipment that could approach the pipelines in a more convenient and less expensive way, and that could inspect the pipelines as it moves round inside the pipelines by driving methods suitable to the three-dimensional shape of the pipeline.
Consequently, mobile robots have been developed that could thoroughly examine the inside of pipelines while driving inside the peculiar and limited three-dimensional space of the pipelines. A lot of research is underway regarding these types of robots.
FIG. 1 is a diagram illustrating a conventional robot for inspecting pipelines, and FIG. 2 is a diagram illustrating a link module of FIG. 1.
As illustrated in FIG. 1 and FIG. 2, a conventional robot for inspecting pipelines is that driving modules 10 installed in front and rear parts of the robot, control modules 20 and battery modules 30 is connected by means of link modules 40. Such a link module 40 is provided with a universal joint such that the robot for inspecting pipelines could be flexibly transformed according to the shape of a pipeline.
However, such a conventional link module 40 only changes the shape of the robot for inspecting pipelines passively according to the shape of a pipeline, and thus is incapable of improving the steering performance of the robot, which is a problem.
Therefore, in order to improve the steering performance of the robot for inspecting pipelines, the link module 40 that connects the modules 10, 20, 30 of the robot for inspecting pipelines must be configured as an active type link module. Furthermore, in order to minimize power consumption, the link module 40 must be configured to maintain its active state only in certain areas.
That is, there is a need to develop an active joint module configured to be at an active state and thus consumes power when driving through a route divergent area (for example, divergent pipeline) but configured to be at a passive state and thus does not consume power when driving through a general area (for example, driving through a straight pipeline), and a robot for inspecting pipelines provided with such an active joint module.